Geophagia, the deliberate ingestion of clayey materials, is a complex eating behaviour with obscure etiology and numerous health/medical problems. Geological, mineralogical and geochemical studies were carried out on Sabga geophagic clayey materials located within a trachyte Bamenda mountain, about 16 km east of Bamenda town (North West Cameroon), in order to define the genesis, and its medical interest. Four (04) samples were characterized by different techniques: description of outcrops and pits, particle size distribution by laser dispersion, X-ray diffraction, Fourier transform infrared spectrometry, Scanning electron microscopy and bulk chemical analyses. The main clay minerals were smectite (49-60%) and kaolinite (4-6%). The other major minerals are quartz (19-34%), feldspar (6-12%), goethite (3-6%), and hematite (1-3%). The average particle diameter varied from 2 to 9 μm. Results from the different analytical techniques point out a meteoric weathering of feldspar as petrogenetic origin of geophagic clayey materials. Smectite and kaolinite, which are the main desirable minerals components of the geophagic clayey materials, were geochemically derived from surrounding trachytes. However the presence of crystalline silica (quartz) up to 2% limits the application of some Sabga geophagic clayey materials for pharmaceutical clays. The high radioactive (Th, U), carcinogenic (Cr, Cu, Pb, Ni) and teratogenic (or birth defects) (Cu, Zn, Pb) elements contents in some Sabga geophagic clayey materials implied some pretreatment.